//
//  UIBarButtonItem+Extension.swift
//  Microblog
//
//  Created by steaest on 15/8/11.
//  Copyright © 2015年 steaest. All rights reserved.
//

import UIKit

extension UIBarButtonItem {

    convenience init(imageName: String, target: AnyObject?, action:String?) {
        
        let button = UIButton()
        
        button.setImage(UIImage(named: imageName), forState: UIControlState.Normal)
        button.setImage(UIImage(named: imageName + "_highlighted"), forState: UIControlState.Highlighted)
        button.sizeToFit()
        
        //设置监听方法 判断action是否存在
        if let actionName = action {
            button.addTarget(target, action: Selector(actionName), forControlEvents: UIControlEvents.TouchUpInside)
        }
        
        //调用指定的构造函数
        self.init(customView: button)
    }
}
